It is necessary to be able to play a stroke of the golf ball in the direction of the sighted target, for example a hole on the green of a course that the player positions himself correctly for the stroke. In this respect, the feet, knees, hips, eyes and shoulders have to be aligned in parallel with a line in the direction of the sighted target. The face of the club should be aligned exactly on the target. If the golfer stands with an incorrect alignment, the ball may pass the sighted target to the side when striking the ball.
Most mistakes in a golf swing result from an incorrect alignment, with the largest alignment problem being the manner the target is sighted. As soon as one stands laterally to the target and wants to hit one's golf ball, the right eye becomes more dominant when one turns and inclines one's head to look toward the target. The visual line, that is the straight line between the eye and the fixated target, is thereby deflected further to the right than it actually is and thus naturally produces an optical illusion. As a result of this, the feet, knees, hips, eyes and shoulders are then often not aligned in parallel with the target line.
Systems and methods for the provision of coaching and training information specific to golf to individual golfers are described in WO 2012/138605 A2 and are based on data which are produced during individual golf strokes. This golf stroke analyzing system comprises a data acquisition and storage apparatus which receives data from a GPS system, from the golf club, from the golf shoes and from a clothing component such as a golf glove or shirt, which processes said data and which forwards them via a network to a portable electrical device and/or to a data hub where the data are stored, analyzed and displayed. In this respect, the data acquisition and storage apparatus can be attached to a golf cart or to a golf bag to which a video camera, an alignment aid such as a laser, a tilt sensor and so on can be attached. Sensors for detecting force data are provided in the shoes, whereas sensors for detecting position data are provided in the golf club and in the clothing component to determine the position of the body part, such as the hands or shoulders, or of the golf club. Such a system and the methods are, however, only adapted to analyze a golf club during or after the execution of this golf stroke. No advance indications for optimizing a specific stroke are possible here.
A portable wireless mobile device is disclosed as a movement detection and analysis system in WO 2012/027726 A2 which comprises at least one movement detection element for coupling with the golfer or with his equipment and an application on a mobile device. The movement detection element comprises a WIFI measuring unit and can be attached to a golf shoe, to sunglasses, to the club face or in the handle of a golf club to detect any combination of position values, speed values and acceleration values. The system and the methods are in this respect also adapted for analyzing a golf stroke during or after the execution of a specific golf stroke or for displaying a training plan. No advance indications for optimizing a specific stroke are possible here either. The movement detection and analysis system is thus not suitable as an alignment aid for golfers before the stroke.
An analysis device for strokes with a golf club is described in the patent application US2010/0099509 A1 in which sensors in the golf club and in a glove deliver signals on the current stroke and said stroke is analyzed in a display device. The determination of a vector to the target is not carried out.
An analysis device for the holding and the stroke of a golf club is described in the patent application US2007/0265105 A1. Three light sources, which are observed and analyzed by a camera, are installed at the golf club for this purpose. The determination of a vector to the target is not carried out.
It is disclosed in the “Alignment Aid Tool” of the iPhone application “Golf Tools Pro” of Brendan Magill (http://www.appticker.de/ch/app/585644/golf-tools-pro.html) that the iPhone is used as a gyroscope to align the feet of a golfer with a selected target. In this respect, in a first step, the target line is sighted by direction finding using a direction marking line on the iPhone screen and is stored. In a second step, a position line and position marks for the feet of the golfer are then shown on the screen which additionally have the image currently recorded by the rear camera of the iPhone superposed on them. In this respect, however, handling is extremely difficult in practice. The iPhone device has to be held with at least one hand with the camera directed to the ground for the alignment of the feet of the golfer. At the same time, the two feet have to be brought into alignment with the position marking or the position line via the current image shown on the screen. The golfer can accordingly not adopt the stroke position in which the grip of the club is fixedly gripped with both hands to propel the golf ball in the direction of the hole in a swing movement, with the club face being aligned by 90° toward the target line.